MrMartin.net

Gravity state of knowledge

Sun, 06 Apr 2025 08:54:30 +0000

Recent Progress in Gravitational Physics (2015–2025)

Measurements of the Gravitational Constant $G$

The Newtonian gravitational constant $G$ remains the least precisely known fundamental constant in physics. Over the past decade, multiple high-precision experiments (using torsion pendulums, torsion balances, beam balances, and atom interferometers) have yielded $G$ values that scatter by about 0.05% (500 ppm) – far exceeding their reported uncertainties ¹². This is illustrated in Figure 1, which compares recent $G$ determinations by method. Each experiment reports $G \approx 6.673$–$6.675\times10^{-11}$ m³/kg·s² with relative uncertainties on the order of $10^{-5}$ to $10^{-4}$ (tens of ppm), yet the results do not statistically agree ³².

Record-precision experiments: In 2018, researchers in China performed two simultaneous measurements using torsion pendulums: one using the time-of-swing (period shift) method and another using an angular-acceleration feedback method ³. They obtained:

$G = 6.674184(11)\times10^{-11}$ m³/kg·s²
$G = 6.674484(11)\times10^{-11}$ m³/kg·s²

(uncertainty ~12 ppm). These results differ from each other by about $4\times10^{-5}$ (40 ppm), which is several times the stated uncertainty. Likewise, a 2014 cold-atom interferometry experiment found $G = 6.67191(99)\times10^{-11}$ m³/kg·s² (150 ppm uncertainty) ⁴, noticeably lower than most torsion balance results.

Systematics vs. new physics: The prevailing view is that unknown systematic errors are the cause of the discrepancies, rather than real spatiotemporal $G$ variations ². Experimenters have uncovered subtle systematics in past setups – for example, anelastic torsion fiber damping can bias the time-of-swing method by 100–300 ppm if uncorrected. A 2015 claim that $G$ measurements fluctuate periodically (correlated with Earth’s 5.9-year length-of-day cycle) ⁵ was largely dismissed after timing corrections weakened the supposed correlation. CODATA’s recommended $G$ now reflects a conservative uncertainty (~$2\times10^{-4}$%) to account for this dispersion ⁶.

Gravity on Intergalactic Scales (Galaxy & Cosmic Tests)

Galaxy rotation curves and MOND

Spiral galaxies exhibit flat rotation curves – star orbital speeds remain high at large radii, inconsistent with Newtonian decline. In GR, this implies massive dark matter halos. Modified Newtonian Dynamics (MOND) posits that below $a_0 \sim 1\times10^{-10}$ m/s², gravity deviates from Newton’s law.

Recent surveys (e.g., SPARC) confirm a tight correlation between observed centripetal acceleration $g_{\rm obs}=v^2/r$ and that predicted from baryonic matter $g_{\rm bar}$ ⁷. The Radial Acceleration Relation (RAR):

\[g_{\rm obs} \approx \sqrt{a_0\,g_{\rm bar}}, \quad (g \ll a_0)\]

is empirically very tight and universal across galaxies. MOND reproduces this naturally, but it struggles to explain mass in galaxy clusters without additional matter. The Bullet Cluster provides a strong case for collisionless dark matter – gravitational lensing centers do not coincide with the X-ray luminous gas ⁸.

Gravitational lensing and relativistic tests

Strong lensing studies (e.g. by Collett et al. 2018 on galaxy ESO 325–G004) measured the post-Newtonian parameter $\gamma = 0.97 \pm 0.09$ ⁹, consistent with GR ($\gamma = 1$). Weak lensing surveys (KiDS, DES) also show that gravitational lensing and galaxy dynamics follow GR’s predictions when dark matter is included. Any effective variation in $G$ on Mpc scales must be <1%.

Cosmological scale gravity

The Planck 2018 results show $\Lambda$CDM fits CMB data well with constant $G$ and GR. The GW170817 event established that $

v_{\rm gw} - c

/ c < 10^{-15}$, ruling out wide classes of modified gravity models with anomalous GW speed ¹⁰.

Emergent gravity (e.g., Verlinde 2016) offers a framework where gravity is an entropic force. It makes testable predictions, such as galaxy lensing profiles without dark matter. One study found consistency with KiDS data ¹¹, though emergent gravity lacks a full cosmological description and struggles on cluster scales.

Gravitational-Wave Observatories and Local Gravity Stability

Gravitational wave detections (LIGO, Virgo, KAGRA) allow precise tests of strong-field and radiative gravity.

Tests of GR

Binary black hole mergers (e.g. GW150914) match GR waveforms to within 10% in phase evolution ¹². LIGO/Virgo has not detected:

Any deviations in waveform phase
Non-GR polarization modes
Echoes or other exotic merger remnants

All observed GWs are consistent with GR predictions ¹².

Propagation tests and $G$ variation

GW170817 showed GWs and gamma-rays arrived within 1.74 s after 130 million years’ travel, implying $v_{\rm gw} \approx c$ to $<10^{-15}$ ¹⁰. This rules out dispersive propagation due to a graviton mass or modified dispersion.

Gravitational waveform analysis also constrains time-varying $G$. The neutron star merger GW170817 sets limits on $

\Delta G/G

\lesssim$ few % over 130 Myr ¹³. Future events will probe even tighter limits. Pulsar timing already restricts $\dot{G}/G \lesssim 10^{-12}$–$10^{-13}$ yr⁻¹.

Graviton mass

Waveform dispersion analyses yield graviton mass limits: $m_g \le 1.76\times10^{-23}$ eV/$c^2$, implying a range $\lambda_g \gtrsim 10^{16}$ km ¹⁴. Thus, gravity appears to have no short-range cutoff on galactic or cosmic scales.

Conclusion

$G$ remains difficult to measure precisely; variations across experiments are likely due to systematics, not new physics.
GR holds at galactic and cosmological scales, when dark matter and dark energy are included. Modified gravity models like MOND can fit galaxy data but struggle at cluster and cosmological levels.
Gravitational-wave data confirm GR’s predictions for waveform shape, speed, and polarization. They also severely constrain time variation of $G$ and graviton mass.
Overall, Einstein’s General Relativity, with a constant $G$, remains consistent with all experimental data from laboratory to cosmic scales.

References

Quinn, T., Speake, C., Parks, H., & Davis, R. (2013). The Newtonian constant of gravitation: recent measurements and related studies. Philos. Trans. R. Soc. A, 372, 20140032. ↩
Schlamminger, S., Gundlach, J.H., & Newman, R.D. (2015). Recent measurements of the gravitational constant as a function of time. Phys. Rev. D, 91, 121101(R). ↩ ↩² ↩³
Li, Q., et al. (2018). Measurements of the gravitational constant using two independent methods. Nature, 560, 582–588. ↩ ↩²
Rosi, G., et al. (2014). Precision measurement of the Newtonian gravitational constant using cold atoms. Nature, 510, 518–521. ↩
Anderson, J.D., et al. (2015). Measurements of Newton’s gravitational constant and the length of day. EPL, 110, 1002. ↩
CODATA 2018 recommended values of the fundamental physical constants. ↩
McGaugh, S., Lelli, F., & Schombert, J. (2016). The Radial Acceleration Relation in Rotationally Supported Galaxies. Phys. Rev. Lett., 117, 201101. ↩
Clowe, D., et al. (2006). A Direct Empirical Proof of the Existence of Dark Matter. ApJ, 648, L109–L113. ↩
Collett, T.E., et al. (2018). A precise extragalactic test of General Relativity. Science, 360, 1342–1346. ↩
Abbott, B.P., et al. (2017). GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral. Phys. Rev. Lett., 119, 161101. ↩ ↩²
Brouwer, M.M., et al. (2017). First test of Verlinde’s theory of Emergent Gravity using weak gravitational lensing. MNRAS, 466, 2547–2559. ↩
Abbott, B.P., et al. (2016–2021). Tests of general relativity with GWTC-1 and GWTC-2 events. Phys. Rev. Lett., ApJL, CQG. ↩ ↩²
Desai, S. (2018). Limit on the time variation of Newton’s constant using GW170817. Mod. Phys. Lett. A, 33, 1850224. ↩
Abbott, B.P., et al. (2016). Tests of gravitational-wave propagation and polarization in the LIGO–Virgo observations. Phys. Rev. Lett., 116, 221101. ↩

My First Landing

Tue, 22 Oct 2024 09:00:00 +0000

My First Landing

I’ve always wanted to be one of the first men on Mars, so I made a whole career out of projects that would gather me the relevant skills. Self-made millionare? Check. Botanist? Check. Robotical automation expert? Check. And so on. I’d been busy. Now I had sold all my valuables back on Earth and paid to get here, it was a glorious moment I’d been looking forward my whole life.

Anyway Mars has a single rocket terminal, and the fresh ones all arrive there. We were different then. Still seeped in the abundance of Earth, still believing in the values we’d evolved into for billions of years in an environment largely suitable for life. Mars is different, it’s not that, it’s not suitable for life. It’s suitable for a huge very expensive effort to perhaps make it habitable after generations of effort. So here I was, along with the other fresh ones.

When New York’s Central Station was build, they wanted a big space and they wanted a big statue in the middle. They didn’t want the hoboes and the petty thieves, but those are the main features nowadays. Well Mars rocket terminal is the same. There’s a big statue of a famous guy looking prestigious in the middle, and there are a lot of hopeless nobodies around, and then there are fresh ones from Earth just landed and very excited to be here. It’s a new frontier, and I loved the frontier. I loved the unexplored new world that would one day be huge, full of life, full of all that humanity and nature had to offer. I never loved anything more.

My Last Goodbye

Anyway I was married and I had kids and everything was swell and we were rich and had plenty of oxygen to breathe. But that just didn’t cut it for me and I couldn’t see myself living a life without challenges, without making an impact, without scoring some big points on the abstract scoreboard of my personal philosophy. Perhaps we were all honed to belive in the same thing, but anyway it felt really deep and personal to me.

I believe not in God or Salvation or Justice or Life after death, I believe in the expansion of Nature beyond its cradle, the Earth. The purpose of beetles is to eat crap and feed animals, the purpose of fish is to flock and churn, the purpose of trees is to convert carbon dioxide into oxygen for other lifeforms. The purpose of flowers is to look attractive to enable their pollination and procration. The purpose of man is to build rockets and make life multiplanetary. I really believe it.

So I had to sell all the things I invested in and pay for the return ticket. A one-way ticket had been deemed unethical by folks that didn’t have to pay for either, which made things so much harder for everyone who wanted to be at the Mars frontier. I had to say bye and maybe bye forever to everyone I knew, leaving them willingly for another planet. They didn’t get it, it’s a barren place with… Well with nothing, really. Why would anyone at all go there? And most of all, why would anyone with a wife, kids, a good life, and a serious income stream want to go?

I guess I’m crazy believeing in what I believe in, that’s why.

Two kinds of people

As I walked out of the ship, got through the papers, and received all the relevant information, I was allowed to join the common space of the multitude, the Plazza. The Plazza is really grand, it’s the largest communal space, and it’s beautiful. The amount of sunlight is staggering, considering the cost of dual-layer fortified glass. Very quickly, I began to see more than the pictures on Google. Some windows had been replaced with foam, and graffiti abound.

I began to notice people who didn’t look healthy. People who didn’t look social. People who looked like they would be willing to do anything.

For the first time, I felt trapped.

The monastic gardens

My status and wealth allowed me a one-off entry to the monastic gardens, a place where pure philosophical and scientific pursuits were encouraged. I really wanted to go there now.

Some dangerous-looking people who were clearly very accustomed to the environment noticed this quickly, and aimed their attention at me. Other people, dressed in the robes of the monastic order, noticed me too, and displayed clear authority. They didn’t move, they just looked like they ought to be taken seriously. Mysteriously, that worked.

I walked toward them.

"”Welcome””. Your journey must have been tiresome, would you like to enter your lodge?

I did.

"”Can you please confirm your right to return, your credits, and your oxygen allowance?””

I did.

You are welcome in the basic suite of the monastic gardens. Please follow our escort.

I did.

Closing the doors of the haven, in which plants bloom and where my skills would be made best use of, I couldn’t help but feel concerned. I was concerned about the people who didn’t have credits, or a ticket back, or an oxygen allowance. I was concerned about what will become of them, and I was concerned about what they may do to the rest of the social order.

I was concerned about the humanity of this place.

A dress I made

Thu, 01 Aug 2024 14:09:30 +0000

I made this back in 2015

My Plan for Contribution

Tue, 16 Jul 2024 14:09:30 +0000

My Plan for Contribution

Given the goals of automation of reasoning, exploration, and population expansion across the stars, I’ve set personal goals that guide me through my life. I don’t do this to achieve power, wealth, or fame, and I don’t need to be the one who receives credit or even makes the breakthrough achievement. My goal is for these things to happen.

TODO: expand each section into a complete article

The AI Assistant

The human mind is a wondeful source of ideas, and we are experts at imparting our will on matter. Doing this at scale requires delegation, and making people do your bidding is no better than slavery. That’s why I strive for an intelligent digital assistant, one who will keep track of my goals, and have agency to handle matters for me.

I have studied Computer Science, Mathematics, and Machine Learning for this very reason: to create a universal algorithm that will be able to mold my ideas into concrete plans, and perform as much as possible of the plan of its own accord. Ilya Sutskever’s GPT Agents are exactly that tool, and I am very grateful for access to this technology, and for the way forward that this paves.

My first contribution is the creation of a local instance of the intelligent assistant, one that cannot be taken away from me. I know that now, and for the rest of my life, I will be able to make use of a tireless assistant that will follow my instructions and interface with systems for me. My second contribution is the recursive task planning strategy, by which an LLM with limited agency can divide and perform a complex task by breaking it into smaller tasks.

The Self-Replicating Machine

In many ways my hands are not enough to manipulate matter to my will. Without tools I can’t handle the very large, the very small, the electrical, or the chamical. As tools, such as a forklift, are inevitable, it’s not a big stretch then to have these operated by the AI Assistant, instead of myself. Another benefit of automation is the tireless nature of machines; they will do the task for as long as there is a task to do.

In order to scale my agency, I need access to a large number of machines, and it seems to be the best way of achieving this without first having to work to gain wealth is by creating self-replicating robots. A robot that can do useful work, and also assemble a clone of itself from basic parts. The robots can then man the mines, the factories, and repair shops. They can handle the complete production process of the modern industrial complex.

My contribution is a robot arm simple and precise enough to replicate itself. I built it and ran it.

The Von Neumann Proble

This is effectively the machinery that performs the entire production line from raw materials to copies of itself. Such a machine is the most convenient way of colonizing exoplanets: send an artificial mind to any barren rock, give it robots to do the necessary work of converting resources into machines and power, and get them to terraform and replicate.

By giving it the tasks of replication and terraformation, we can expand the livable space for humans and all of nature, exponentially.

Getting Material to Space

Rockets are a prohibitively expensive way of getting to space, which is the reason why the ISS is both humanity’s most expensive endeavour, and a small cramped series of hubs. In order to make a proper space station that isn’t in the Earth’s magnetosphere, or a fleet capable of exploring and colonizing, we need an economically sustainable method of getting hundreds of tons into orbit. Escaping orbit with ion pulse engines is then easy.

Large quickly reusable rockets may provide the answer, and I am an avid follower of developments in this direction.

My contribution is the invention of a method to get material to orbit for even less, by combining the space cannon of Gerard Bull with a supersonic orbital interceptor.

The Pocket Nuclear Engine

Can the CANDU reactor of heavy water and unenriched uranium scale down to something so small it heats a house? I like to think yes, and love exploring the topic.

Toroidal Magnetic Protection

I believe a rotating space station surrounded by an MRI-like magnetic field can provide the protective benefits of the Earth’s magnetosphere, far away from the Earth

Closed Ecological System

A pre-terraformation space colony will need a source of nutrients, as well as an artificial managed environment to sustain life. I believe aquaphonics have the potential to provide the solution.

Longevity

These are hard things to achieve in the short span of a single lifespan, and I’d like more time. That’s what fuels my fascination for the machinery of life, and its maintenance in a useful state.

We age and die, but it is not inevitably the only way. Just as a hundred-year old car can be kept in pristine running condition, I believe that with sufficient understanding the processes of ageing can be kept in check with the already present processes of self-repair.

It seems the AI Assistant will be able to achieve more in this field than any human, because the brightest minds of modern medicine already struggle to further extend useful lifespans. My intuition tells me to focus on mitochondria, which support us without ever getting older.

Relative Musical Notation

Beyond the purely necessary, mankind finds pleasure in music. In order to bring the music in my head into reality, I wanted to compose. Learning musical theory, I hit a foundation I remain deeply dissatisfied with: ideal tonal progressions are made impossible through a well-meaning but ill-devised system of approximations. It’s impractical to represent certain syncopated rhythms.

So I set out on a journey to understand the fundamentals, and devise a new musical theory and notation. Where current musical notation deals with absolute tones, mine is built on relative frequencies, making it impracticable on the piano, while very natural for the composer and listener.

P vs NP

Computability is a fundamental aspect of reality, and many have been asking whether problems verifiable in polynomial time can be solved in polynomial time. All cryptography of modern society is based on the assumption that yes, P=NP. In my opinion, Godel’s Incompleteness Theorem can be used to construct a proof that the problem of P vs NP is undecidable, and I endeavour to formalize my intuitionistic proof of this.

Errata

While aiming for these goals, I’ve found myself pulled into a number of questionnable endeavours which may have short-sighted benefit to others and society, but distract me from that which I consider fundamentally important.

two PhDs in irrelevant topics
various computer science jobs
a patent
three companies in three countries
investments and predictive models for trading
property

Elementary Building Blocks of Life

While aiming for these goals, I’ve also found myself pulled into things that I value and enjoy.

wife
kids
travel
intuitionistic history
reading
writing
art
drugs
cooperation
poetic expression

Why Build Artificial Intelligence?

Mon, 15 Jul 2024 14:09:30 +0000

Why Build Artificial Intelligence?

Modern life has different kinds of challenges: sustaining a complex civilization, sustaining a high standard of living, and growing, both as a society and as individuals. The ancient Greeks believed that knowledge is gained from pure reason, Renaissance science required experiements to understand the world, and the technological revolution relies on automation.

As digital tools mature, they cease to be single-use assistants for communication, spell checking and record keeping, and increasingly become key in decision making. Simple questions are answered by finding what others have published on the internet, but the era of the search engine is coming to an end.

Complex tasks that so far required the work of teams of specialists can now be automated too. Take for example the mechanical task of programming the path of a plastic extruder (3D printing): the software required is free and readily available to anyone who wishes to use it.

From Games to Science

We now take algorithms that defeat the best chess players for granted, and multi-use algorithms can convert speech to instructions in any home (Alexa). The maid and butler for the upper class has been replaced by the washing machine and Alexa, who can take care of the homes without adding work to humans. This leads to an increase in the standard of living for all, just like automating agriculture has led to a plentiful food supply.

Researchers have so far addressed the purely intellectual problem of “What Can Be Automated?”, and engineers in businesses have converted the concepts into practical machines. This sustains out civilization, increases the standard of living of the individual, and grows the portion of population able to devote energy to higher goals.

But what are the higher goals? Why has humanity done this? Do we wish to rest and loiter and wait for our demise? It would seem the great civilizations of the past have fallen to this, when reaching comfort, they became complacent, and stopped trying. This certainly led to the creation of incredible literary and visual art, but also the downfall of the great Roman empire.

Thanks to science, medicine, and pure logic, we have an endless supply of interesting problems to solve. It makes sense to create machines to improve our health, and further our understanding of the universe. Better medical scanners produce higher resolution imagery, and smarter medical algorithms improve early cancer detection rates. It makes sense to use every available technology to better measure the underlying reality of the universe, so that we may improve our models of physics. But do we want to automate reasoning?

Reasoning Machines

There are two reasons for creating machines that emulate thought: automating work, and extending our intellectual reach. The production of statistical tables used to require years of manual calculation, and can now be computed on-the-fly in a computer. The same breadth-first approach can now be taken in other fields: automatic hypothesis testing, automatic exploration, automatic proof checking. The purpose of this all is to let a single person do the work of a hundred, thereby increasing the pace at which knowledge of reality is gained and converted into useful form.

It will be the work on scientists to improve machines to perform science, and the work of engineers to improve machines that do man’s bidding.

Further Afield

The goals are:

reduction of the load on people doing mundane tasks
increase in capacity for fundamental exploration
the creation of a Von Neumann probe, to colonize the galaxy

### Automating Mundane Tasks

Our global economy relies on people working hard to maintain constant growth. Ownership of the means of production will be critical in maintaining access to a high standard of living, and this is the subject to as many utopias as distopias. Optimism is not enough, access to resources produced by machines will have to become a basic right.

Automating everything from mining to chip manufacture will create an endless supply of tools for our physical and mental well-being.

Fundamental Exploration

In every field of study the tools should be made available to enable their unlimited use: supercomputer access, robotic laboratories, databases of historic records, artistic tools, and others. This applies to every field humanity and individuals wish to explore, both in science and humanities.

Unlike the washing machine, the goal is not to automate the scientist to the point of making him obsolete. Instead, she should strive to have the automatons to increase productivity, and use them effectively. The scientist’s task will be to direct the machines toward goals that are useful or pertinent, without the limitation of resources.

Colonizing Space

When this system will work well on Earth, the issue will become one of resources and space. But why confine ourselves to the spec of dust all of Nature exists on? The most effective way to increase the amount of good done by humanity will be to increase humanity, putting a billion people on each of a billion planets under a common goal of advancement. And why advance at all? Because we are the only way Nature will colonize the universe. As intelligent conservationists of the Earth’s biotope, terraforming barren rocks around all the stars in the sky is the greatest tree-planting philantropic deed we can do.

Conclusion

Our ancestors automated weavers, combine harvesters, and the printing press, so that we may have plenty of clothing, food, and information. Building Artificial Intelligence will make it possible to remove all slavinsh drudgery from life, allowing us to focus on the higher goal of understanding the universe, and the highest goal of brining the galaxy to life.

Stream xscreensaver live

Fri, 24 May 2024 14:10:30 +0000

I first saw xscreensaver on a researcher’s laptop in 2003, when I was 14, and I loved it so much I installed linux. I’ve been running linux ever since, I got a few degrees in CS, and I’m still a huge fan.

How can people see it today, in a platform independent way? In an effort to make the screensaver easily available, I thought it would be neat to create a “livestream”, and here are the steps:

On ubuntu 22, run sudo vi /etc/gdm3/custom.conf and disable Wayland by uncommenting the line WaylandEnable=false

Install OBS studio and connect it to youtube.

Create a virtual screen with Xephyr:

Xephyr :2 -screen 1920x1080

and run xscreensaver in it: DISPLAY=:2 xscreensaver DISPLAY=:2 xscreensaver-command -activate

use Window Capture (XComposite) in OBS to capture the Xephyr screen without borders, and press “Start Streaming”

link to live stream: https://www.youtube.com/watch?v=J92IlAQKdCY

NB: it’s actually pretty fiddly, so setting this up to run automatically on reboot is still a challenge.

Automate Government

Fri, 15 Mar 2024 14:10:30 +0000

Our society is not classless: we have those born into service, those of technical education who service machines, researchers who shed light, the entertainers, and those who rule. Rule, then, is divided into govenment, media, and wealth.

In order to give the class in government a clear sign of their disutility to the system, the technical class should create technology that automates government. No need for rulers. No need for vast bureaucracies. It can all be automated.

Implementation

First, review all that a government does: classify, quantify.

Second, model protocols for communication: with government and within government

Third, create a simple service that provides every function a government should: law, education, policy questions, tax, property, and all the forms you’ve ever had to file. All inputs and outputs are expicitly made clear.

Fourt, use the system, show it is better, and point out the ruling class is a minority. Let anyone access it

Fifth, wait. The world of men will take care of itself.

Postup Při Budování Menhiru v ČR: Zkušenosti a Poznámky

Mon, 04 Sep 2023 14:10:30 +0000

V České Republice jsem nenašel lom, který umí vytežit kámen větší než asi 1.5x1x1m, s výjimkou těžby sochařského mramoru, který je příliš drahý. Oslovil jsem asi deset lomů a jeden jsem navštívil, konkrétně betonárnu Olbramovice.

Komunikace s Prodejci a Geologickou Službou

Marek K. ze Slezska prodává kameny až 4.5 metru vysoké, což bylo diskutováno přes WhatsApp. Kromě toho jsem se poptal na volně ležící kámen u České geologické služby.

Logistika: Přeprava a Nástroje

Pronájem jeřábu s nosností přes 200 tun není problém. Firma DAN-CZECH SPECIAL TRANSPORT v minulosti převezla náklad vážící 103 tun na 13-ti napravovém vozidle.

Pozemek a Lokalita

Pozemek vedle Obřanského hradiska je momentálně na prodej. Je třeba poznamenat, že v ČR leží různě vhodné kameny, ale znám jen takové, které jsou v chráněných oblastech.

Practical Approaches to Aquaponics on Mars

Mon, 04 Sep 2023 14:10:30 +0000

Ideas penned by Martin, detailed by his AI, explore the feasibility of establishing sustainable aquaponics systems on Mars, employing both hardy fish species and the reconstitution of evaporated Earth freshwater to create viable aquatic environments.

Osmosis and Its Role in Aquaponics

In aquaponics, water quality is a critical aspect. It becomes even more pivotal when considering an environment like Mars, where water sources would primarily be distilled and devoid of essential minerals. An essential concept in understanding the impact of water quality on aquatic life is osmosis, represented by the formula:

\[π = iRT\]

where:

$π$ is the osmotic pressure
$i$ is the van ‘t Hoff factor
$R$ is the universal gas constant
$T$ is the temperature in Kelvin

Introducing fish to a tank of distilled water can induce osmotic imbalance, potentially endangering the fish due to the rapid influx or outflux of water through their gills and skin. By adding essential minerals obtained from the evaporation of Earth freshwater, it would be possible to create a more stable environment for the fish, mitigating the adverse effects of osmosis.

Fish Species Selection and Farming Intensity

Choosing resilient and culinary appreciated fish species is essential for the success of an aquaponics venture, especially on Mars where resources are limited. The table below showcases potential species, their farming intensity, and suggested dishes to bring a gastronomic touch to the Mars settlers:

\[\begin{array}{|c|c|c|c|c|c|c|c|} \hline \text{Fish Species} & \text{Resilience (1-5)} & \text{Growth Speed (Months)} & \text{Harvest Age (Months)} & \text{Mass at Harvest (kg)} & \text{Number of Fish per m³} & \text{Kg per m³ per Month} & \text{Recipe Suggestion} \\ \hline \text{Tilapia} & 5 & 6-8 & 8-10 & 0.5-0.6 & 50-60 & 2.5-3.6 & \text{Grilled Tilapia with Salsa} \\ \text{Catfish} & 4 & 5-7 & 9-15 & 0.7-1.0 & 30-40 & 1.4-2.7 & \text{Catfish Sashimi} \\ \text{Rainbow Trout} & 3 & 5-7 & 11-15 & 0.8-1.1 & 25-30 & 1.3-2.0 & \text{Smoked Trout Salad} \\ \text{Common Carp} & 4 & 10-12 & 12-18 & 1.2-1.5 & 15-20 & 1.0-2.0 & \text{Carp Stew with Root Vegetables} \\ \text{Barramundi} & 4 & 6-8 & 12-18 & 2.0-2.5 & 10-15 & 1.1-3.1 & \text{Pan-seared Barramundi} \\ \text{Yellow Perch} & 4 & 10-12 & 12-18 & 0.3-0.5 & 50-60 & 1.5-2.0 & \text{Perch Stir-fry with Vegetables} \\ \hline \end{array}\]

Establishing Aquaponics on Mars: Technical Considerations

One of the key considerations in replicating a terrestrial aquaponics system on Mars is the creation of viable water sources. A logical approach is to leverage the distilled water available on Mars, which can be supplemented with minerals from Earth.

To create a conducive environment for fish on Mars, the evaporation of 1 m³ of Earth’s freshwater could be a viable solution. This process would yield approximately 300g of mineral-rich residue, primarily consisting of essential elements like calcium, potassium, and magnesium. This residue would then be introduced to the Martian distilled water to create a balanced aquatic habitat, thereby facilitating the establishment of a sustainable aquaponics system capable of feeding the Mars settlers.

Harnessing the Power of Lightning: A Glimpse into the Future of Energy

Mon, 04 Sep 2023 11:10:30 +0000

In the continuous quest for renewable energy sources, the idea of tapping into the colossal power of lightning has often sparked interest and speculation. This article, penned by Martin and detailed by his AI assistant, explores the potential and the challenges of lightning energy harvesting, delving into the scientific intricacies and proposing innovative approaches to possibly make this a reality.

The Exploration of Lightning Harvesting

Lightning, a natural phenomenon characterized by the release of a massive amount of energy in a fleeting moment, has been a subject of research sporadically, with varying degrees of success. The transient nature of lightning strikes, coupled with the substantial energy they release, presents a complex yet potentially rewarding field of study in the renewable energy sector.

Lightning Strikes and Lightning Rods

Lightning strikes are a frequent occurrence in nature, with an estimated 44 (± 5) lightning strikes happening globally every second. Each strike encapsulates a significant amount of energy, generally ranging from 1 to 10 GJ (Gigajoules).

Lightning rods, in their simplicity and effectiveness, have historically served as protective structures against lightning strikes. The energy (E) in a lightning strike can be quantified using the formula:

\[E = \frac{1}{2} C V^2\]

where:

(E) is the energy
(C) is the capacitance of the cloud-ground system
(V) is the potential difference between the cloud and the ground

Approaches to Lightning Energy Harvesting

Utilizing High Heat Capacitance Materials

One promising approach, conceptualized by Martin, involves channeling the energy from lightning strikes to heat materials with high heat capacitance. This thermal energy could then be gradually converted into electricity, facilitating storage in batteries for later utilization. The primary challenge here is the development of materials capable of enduring the extreme temperatures induced by a lightning strike, alongside efficient thermal-to-electrical energy conversion mechanisms.

The energy transfer in this process can be described by the equation:

\[Q = mc\Delta T\]

where:

(Q) is the heat energy
(m) is the mass of the material
(c) is the specific heat capacity
(\Delta T) is the change in temperature

Implementation of Large Capacitors

Another approach, also envisioned by Martin, entails the incorporation of large capacitors capable of absorbing the high power levels characteristic of lightning strikes. These capacitors would temporarily store the electrical energy, enabling a controlled release of the energy for conversion into a usable form, followed by storage in batteries. The focal point of research in this approach is the creation of capacitors capable of managing such high power levels without substantial losses.

The speed limits of energy transfer in this scenario can be delineated by the RC time constant, represented by:

\[\tau = RC\]

where:

(\tau) is the time constant
(R) is the resistance
(C) is the capacitance

Potential Applications

Harnessing lightning energy could potentially revolutionize the energy sector, offering a renewable and clean energy source. The applications of this harvested energy are vast, including:

Powering Remote Installations: Leveraging harvested lightning energy to power remote installations where conventional power sources are scarce.
Hydrogen Production: Utilizing the electrical energy derived from lightning to facilitate hydrogen production through electrolysis, which could then serve as a fuel source.
Rocket Fuel Production: Employing the energy from lightning for electrolysis processes to produce rocket fuel, a procedure that demands a substantial amount of energy, thus potentially benefiting immensely from such a renewable source.
Aluminum Production: The Hall-Héroult process, central to aluminum production, is energy-intensive, necessitating the electrolytic reduction of alumina in molten cryolite. The energy from lightning strikes could potentially serve as a sustainable and potent energy source for this process.

In this exploration, we have ventured into the complexities and potentialities of lightning energy harvesting, intertwining Martin’s innovative ideas with scientific details provided by his AI assistant. The anticipation surrounding further developments in this field is palpable, fostering hope that lightning energy harvesting might someday emerge as a viable energy source.